Tracer mechanism



July 31, 1951 1.. TANCRED TRACER MECHANISM Filed March 21, 1945 sSheets-Sheet 1 w W. L. TANCRED TRACER MECHANISM July 31, 195] 6Sheets-Sheet 2 Filed March 21, 1945 INVENTOR. fZZZlflwffdwzfi July 31,1951 w. 1.. TANCRED ,5

TRACER MECHANISM Filed March 21, 1945 6 Sheets-Sheet 5 LN VEN TOR.

July 31, 1951 w. L. TANCRED 2,562,234

TRACER MECHANISM Filed March 21, 1945 6 sheets-sheet 4 IN V EN TOR.

Jul 31,1951 w. L. TANCRED TRACER MECHANISM e Sheets-Sheet 5 Filed March21, 1945 w f/ W IN V EN TOR. WZZ, [fa/21w July 31, 1951 w. L. TANCREDTRACER MECHANISM 6 Sheets-Sheet 6 Filed March 21, 1945 IN V EN TOR. iizmzd www Patented July 31, 1951 atta n TRACER MECHANISM William L.Tancred, Springfield, Vt, assignor to Jones & Lamson Machine Company,Springfield, Vt., a corporation of Vermont Application March 21, 1945,Serial No. 584,003

Claims. 1

trace the pattern with great accuracy and whichwill automatically followaround the pattern contour throughout a complete circumference when oncepresented thereto. To these ends the tracer comprises a pair of normallyconcentric elements, one enclosing the other, the pattern-engagingfeeler carried by the outer of these elements, and both being yieldinglyfulcrumed at spaced points to an outer casing, the fulcrum points of theinner element being much nearer to the feeler than the fulcrum point ofthe outer element. A slight movement of the feeler in any directionbrings the two elements toward each other remote from the feeler andactuates a feed or traverse control, or both. After contact between theelements is established, a return relative motion of the control whichmoves the feeler or Work is produced, tending to cause separation of theelements remote from the feeler. These motions of the two elements arethen caused to control motors for moving the tracer and pattern inangularly related directions, the tracer following the pattern so that atool may follow the same path as the tracer onthe pattern relative to.work.

Another object of this invention is to provide a synchronization oftracer control movements to energize tool, head motors for uniform andcontinuous cutting of work to conform with the pattern contour. Thus, ifthe operator should leave the machine, the tracer will continuouslyrepeat over the pattern contour path until the machine is stopped.

A further object of the invention is to provide a tracer and patternmounting for a turret lathe whereby the tracer and pattern may controlthe operationof a tool at one tooling station of the turret but will notinterfere with any desired op-erationsat other tooling stations of theturret for which settings have been made.

For a more complete understanding of this invention, reference may behad to the accompanying drawings in which Figure 1 is a cross sectionalview on line I! of Figure 2 through a tracer and controlling valvemechanism embodying the invention.

Figures 2 and 3 are sectional views on lines 2--2 and 3-3, respectively,of Figure 1.'

2 Figures 41 and 5 are sectional views on the correspondingly numberedsection lines of Figure 2. Figure 6 is a perspective view partly insection of the tracer and related parts.

Figure 7 is a diagrammatic View of the power 7 system of a machine toolcontrolled by the tracer mechanism of Figures 1 to 5, inclusive.

Figures 8 to 15, inclusive, show various controlling positions of thetracer elements corresponding to relative tracer and work positionsshown in the correspondingly numbered views with the addenda a as 8a to-15a, respectively.

Figure 16 is a view similar to Figure 2, but showing combined electricaland hydraulic mechanism V Figure 17 is a sectional view on line I1l'l ofFigure 16, together with a diagram of the power system and controls.

Figure 18 is a view similar to a portion of Figure 1, but showing amodification.

Figures 19 and 20 are top planand front elevational views, respectively,of a turret lathe showing the tracer and pattern control of thisinvention applied thereto for operation at onefof the turret toolingstations.

Figure 21 is a detail sectional view on line 2l-2l of Figure v20.

Figure 22 is a sectional View to a larger scale on line 22-22 of Figure19.

Referring first to Figures 1 to 6, there are shown a tracer and powercontrolling devices actuated thereby As shown the tracer comprises acasing I having a tubular portion 2' seated in a hole 3 in a valvecasing 4. To the lower end of the casing I there is secured a taperednose 5 partly closed by a cap 6 perforated at 1. Through thisperforation extends loosely an end portion 8 of a tubular element 9. The.element 9 is provided with a diaphragm Ill outwardly extended therefromand whichforms a universal pivotal connection of the element 9 with thecasing I. As shown the outer margin of the diaphragm was clamped betweenthe upperfend of the nose 5 and an internal shoulder ll of the portion2. The member .8 which closes .oii the lower end of the element 9 isprovided with a feeler element l2, which as will later appear, contactsthe edge of a pattern, such a pattern being shown in Figures 8a to 150,at l5.

Within the tubular element 9,;and normally slightly spaced therefromlandin parallel relation therewith, is the normally coaxially arrangedelement 20. This element 20 is also pivoted to the casing l as at thenose 5 by a diaphragm, this diaphragm being shown at 22 and. being pro-3 vided with holes therethrough at 23 through which spaced segmentalprongs 25 at the lower end of the element 9 loosely extend, as shownbest in Figures and 6.

The lower end of the element is shown as terminating in a ball portion26 which normally is slightly spaced from the inner conical surface 2'!of a sleeve 28 threaded into the lower ends of the prongs and held inplace as by an externally threaded check nut 29. It will be noted thatthe pivoting diaphragm 22 for the inner member 29 is much nearer to thefeeler element I2 than is the pivot diaphragm H! for the outer element9, as shown, for example, the ratio being 1 to 10. When the element I2is contacted on any side face against the edge of a pattern such as I5,pressure exerted against the feeler rocks the lower end of the element 9out of its normal position about a portion of the diaphragm ID as afulcrum, and this correspondingly rocks, but in the opposite direction,the upper end of element 9 and a flange element 30 secured thereto, partway toward the dotted line position of Figure 6. Meantime the innerelement 20 remains stationary in the full line position of Figure 6. Assoon, however, as the lower end of the feeler element 9 engages thelower end of the feeler element 29-, and starts to swing the element 20about its pivot diaphragm 22, the upper end of the element 20 is swungin the same direction as was the upper end of the element 9, but at afaster rate because the lever arm of the element 20 above the diaphragm22 is much greater than the lever arm of the outer element 9 about itsfulcrum diaphragm l6. Thus by the time the elements 9 and 30 havereached their dotted line positions of Figure 6, the element 20 hasreached its dotted line position also, but because when the elements 9and 30 first started to move the element 20 was stationary, andthereafter the upper end of element 20 moved faster than the upper endof the element 9 and the element 30, the relative direction of motionbetween the upper ends of elements 20 and 39 during the motion ofelement 20 was reversed to such relative motion while the element 20 wasstationary. This reversed direction of relative motion is employed toefiect a control of a tracer moving mechanism in a direction opposite tothat produced by the first motion of the outer element 9 alone and for apurpose which will later appear.-

As shown in Figures 2 and 6, the flange member 30 has fulcrumed thereona pair of levers 49 and' 4|. The fulcrum points are arranged 90 apartrelative to the axis of the member 30. One arm 42 of the lever 49 ispivotally connected to a flex ible link 43 leading to a sliding valvemember 44. The corresponding end of the lever 4| at 45 is connected by asimilar link 48 to a pilot valve member 41. The opposite end of each ofthe levers and 4| is connected by a flexible link such as 48 extendingthrough holes 49 in the member 9 and secured in holes in the member 28.Thus as the upper end portion of the outer or feeler element 9 is swungshort of contact with the inner element 29, one or the other, or both,of the fulcra of the levers 40 and 4| are moved in a correspondingdirection which results in corresponding motions of the pilot valves 44and 41. As soon, however, as the innerelement 29 is contacted by theouter element and moved thereby, the inner element at its upper endmoves in the same direction as did the outer element but at a fasterrate, this actuating either one or both the levers 40 and in the reversedirection and l causing a corresponding reverse direction of motion ofthe valves 44 or 41, or both.

Means are provided for yieldingly normally centering the elements 9 and29. As shown such mean comprises, besides the inherent flexibility ofthe diaphragms l5 and. 22, a coiled helical spring 59 (Figure 2). lhisspring is interposed between a pair of abutments El and 52 which arenormally pressed in opposite directions against annular shoulders 53 and54 at opposite ends of a tubular casing 55. This casing 55 has anoutwardly directed flange 5% between its ends, which is held against aninternal annular shoulder 5'! on the casing part i by engagementtherewith of an annular flange projecting inwardly from a cap iii whichnormally closesthe upper end of the casing i and is threaded into theupper end thereof. The casing 55 may be centered by adjusting screws E32threaded through the casing i and engaging the outer face of the casingeach of these screws being provided with a check nut 84. The abutment 5!is provided with a stem 65 having a ball end. 65 which slidably engagesin a cupshaped extremity of the element 20. The abutment 52 is providedwith a conical tubular stem 68 surrounding the stem 65 and with itslower end slid-ably engaging the internal wall of the element 9. As theupper end or" the element is moves laterally, its engagement with thestem causes this stem to tilt, thus compressing the spring 58 on thecorresponding side, this spring then tending to press the abutment 52against the shoulder 55- throughout its circumference and centering thetil coaxially with the element 9. Similarly, lateral motion of the upperend of the element 23 causes the stem 65 to be tilted, bringing thecorresponding outer edge portion of the abutment 5! away from contactwith the shoulder 53, this being opposed by the righting action of thespring 50 which tends to hold the abutment 5i in engagement throughoutits circumference with the shoulder 53 and with the stem 65 coaxial withthe element 20. Thus the spring 5s tends to center each of the elements9 and 2% whenever they are displaced from normally coaxial spacedrelation.

Each of the pilot valves 44 and 41 is a spool valve having a pair ofspaced annular valve close ing portions 15 and H, which, on axialmotion, control communication between central and end passages 52, T3and i i which lead to the center and end portions, respectively, ofcorresponding reversing valve casings 75 and control the positions insuch casings of a pair of reversing valves "58 and "19. The passages 12leading to the central portions of the pilot valves 4 1 and 4? are incommunication with a fluid pressure pipe 81' which also leads to thecentral reduced diameter portions El of the reversing valves 18 and ill.

As shown best in Figure 3, each of these reversing spool valves isprovided with tapered central extensions 85 at their opposite ends whichmay extend through and close correspondingly tapered openings in valveplates 86. As soon as pressure actin on the end of either of these stemsfrom the passages 13 and 14 causes the reversing valve to move in the0pposite direction, the adjacent tapered end 85 opens a bleeder passage8? through the plate 86. The plate 8-5 is provided with passages 88leading from the bleeder passage 3'! to the adjacent end of thecorresponding spool reversing valve and the pressure is equalized atopposite ends of this valve through longitudinal ports 39 through thevalve. he bleeder passage 8'! at each "end of each of the reversinvalves leads through Lileeder ports 99 to a discharge passage 9!. Thispassage also communicates with the interior of the casing l and receivesfluid drain through longitudinal holes Hill of valves 44 and 4! passingthereinto around the stems 43 and 46 of the pilot valves (see Figures 2and 6). This construction provides for a sensitive floating aetion ofthe pilot valves, the central spool portion of which controls thepassage of fluid under pressure from the pressure pipe 99 to eitherpassage l3 and M to the reversing valves. A'guard 92 directs thedrainings into the passage 9|.

In Figure '7 is shown diagrammatically the pressure system of whichthese valves form a trol of the axial positions of the reversingvalvesand consequently a sensitive control of the rate of flow of: the fluidunder pressure to the motor cylinders I29 and I2 I.

In Figure '7 the showing is diagrammatic, the fluid connections andvalve construction having been laid out'to simplify the relation oftracer head and valves to their respective motors or power cylinders.Pressure line 89 feeds both reversing valves at 18 and i9 and pilotvalves at 1 and 47. Movement of either pilot valve, or both will causeflow to end chambers encasing pistons 85 of their respective reversingvalves. The small areas of pistons 85 will amplify movement of valves 18or 79 or both for reater supply to their cylinders 29 or i2! throughconnections [22, i23, I2 2, !25. The connections to the discharge'pipe9| from the pilot valves being illustrated as from theclosed ends ofpilot valve cylinders and from the interior of the casing l, as alsoshown in Figure 3, longitudinal ports l90 tend to equalize backer drainpressure on the ends of the pilot valves. 1

The effects of motions of the tracer elements 9 and 29 in controllingthe relative motions between the tracer and pattern and the correspondonpressure rise above a desired pressure level.

The delivery from the pump passes to anaccumulator i H and opens intothe valve casin N32. The valve it! is provided with two enlarged endportions H2 and H9 and is also provided with an oppositely taperedcentral portionlM'.

In the on position shown in Figure 7, the portion l [4 is positionedbetween the supply passage I 15 leading from the pump and the dischargepassage H5 returning to the tank I95 through a pressure relief valve H!set to give a predetermined back pressure. In the position of the partsshown the fluid under pressure passes the valve 19! into the pressurepipe 80. On moving the control'handle H13 in clockwise direction thevalve portion [is may more or less throttle the supply pipe H5 untilfinally it opens passage to the discharge pipe H6 whereupon pressure inthe pipe 89 'is lowered to that determined by the setting of the reliefvalve I ll.

Pressure derived from the pipe 89 leading to the pilot valves 24 and 4'!controls the positions 'of the booster or reversing valves 79 and 18,which, in turn, control the supply and discharge from the pressure pipe80 to opposite ends of the power cylinders I20 and IZI, the cylinder l2!having the pipes I22 and E23 leadingfrom the casing of the booster valve18 to opposite ends thereof and the cylinder I26 having similar pipes I25 and I from opposite ends thereof leading to the casing for the boostervalve 19. The power cylinder I29 is connected in the Well understoodmanner to cause longitudinal traversing motion of a slide which carrieseither the pattern or the tracer and the power cylinder I2! is caused toproduce lateral or feeding motions of this carriage at right angles tothe motion pro duced by the power cylinder I20 and the motions of thiscarriage are thus controlled by the relative positions of the tracerelements 9 and 20 as the feeler i2 is brought into contact with the edgeof the pattern. Figures 19 to 22 show such a mechanism as applied to aturret lathe and this will be described later.

The arrangements of the pilot and reversing valves provide for a verysensitive control of the power'cylinders. The tapered valve portions 85of the reversing valves provide a sensitive coning relative motionsbetween the tool and work are illustrated diagrammatically in Figures 8to 15 and 8a to 15a. For example, Figure 8 shows diagrammatically therelative positions of the pilot valves, the tracer elements, and theircon-' nections when the feeler 9 is brought against the edgeof thepattern 55 in the position shown in Figure 8a. It will be noted herethat the i lower end of the element 9 carrying the feeler is pressedagainst a straight edge portion-of the pattern 15 and in a directionsuch that the feeler is displaced forwardly while the upper end of theelement '9 is pushed upwardly out of concentric relation to the element29 as shown in Figure 8. This positions the pilot valves ll and 44 insuch a manner as to admit pressure to move the tracer along the patternto the left and to press the tracer backwardly against the edge of thepattern in the direction shown by the arrows of Figure 8a. Continuedpressure of the element 9 toward the edge of the pattern causes theelement 9 to engage the element 20 and move 'it therewith. This causesthe upper end of the element 29 to be moved backwardly faster than theelement 9 to the position shown in Figure 9a, which results in rockingthe lever 49 in a direction to cause reversal of the flow through thepilot valve 4:3 while the flow continues in the same direction throughvalve 41 as shown by the arrows in Figure 9a This results in reversingthe direction of motion of the longitudinal motor H9, thus moving thetracer as a unit away from the pattern edge, while continuing its motioncrosswise in the direction shown by the arrows in Figure 9a, though the'feeler remains in contact with the pattern edge.

This returns the parts toward the condition of Figures 8 and 8a, exceptfor the progress of the tracer to the leftwhich has been going onsteadily. When this condition is again reestablished, the direction ofmotion of the longitudinal slideis again reversed (see Figures 8 and 8a)and feeds toward the edge of the pattern. This condition of oscillationof. the tracer toward and from the edge of the pattern While the feelermaintains'contact therewith, and is being traversed therealong,continues until the tracer contacts with the edge of the pattern at whatis commonly termed a critical angle where its direction is being changedas shown in Figure a. Since at that point the traverse motion, as wellas the feed motion, presses the feeler against the pattern, the element9 is offset by such contact relative to the element 20in an angulardirection, which moves the valve 41 in a direction to increase the feedto the left and to move the valve 44 to feed rearwardly as shown by thearrows in Figure 10a. This angular displacement of the tracer causescontact of the element 9 against the element 20 in the same direction asshown in Figure 10a which relatively displaces the upper ends of theelements 9 and 20 as shown in Figure 11. This not only causes reversalof flow through the valve 44, but also a slower reversal through valve41, resulting in motion of the tracer both forwardly and to the right asshown by the arrows of Figure 11a, and this action takes place while thetracer parts again approach the conditions of Figures 10 and 10a. aswhen feed of the tracer toward the pattern edge is reestablished. As thetracer continues to pass around the end portion of the pattern as inFigures 12 and 12a, the tracer elements 9 and 20 take successively thepositions of Figures 12, 12a to 13 and 13a, rapidly alternating thedirections of motion of the cross slide while the longitudinal slidecontinues to move forwardly as shown by the arrows in Figures 12a and13a, which illustrate by their respective lengths the relative speeds ofthe forces applied.

As the tracer proceeds with its feeler in contact with the pattern, thetracer mechanism moves from the position shown in Figures 12a and 13atoward the position shown in Figures 14a and 15a. It will be noted thatnow the feeler is engaging the front edge of the pattern rather than theback edge as it was doing in Figures 8a and 9a, consequently the lowerend of the feeler is being pressed backwardly from its normal positioninstead of forwardly as in the positions of Figures 8, 8a, 9 and 9a.When the feeler is displaced to an extent short of engagement of theelement 9 with the element 20, as is shown in Figures 14 and 14a, theupper end of the element 9 carrying the flange 30 is displaced forwardlyrelative to the center of the upper end of the element 30, this being inthe opposite direction to the showing of Figure 8. This causes thevalves 44 and 41 to take the position shown in Figure 14, reversing thedirection of flow through both of these valves and so reversing thedirection of motion of the traverse and feed motors so that the traceris then moved along the front edge of the pattern opening to the right,which is in the opposite direction to the movement shown in Figures 8aand 9a when the tracer traverse motor is moving the tracer to the left.There is also a small component of motion pressing the tracer forwardlyto press its feeler against the pattern edge, the relation and relativemagnitudes of these forces being shown by the arrows in Figure 14, whichit will be noted are opposite to the forces shown in Figure 8a. Thismotion of the tracer forwardly takes place until after the lower end ofthe element 9 has contacted and moved the lower end of the element 20,whereupon the upper end of the element 29 moves faster than the upperend of the element 9 and in the same direction so that the parts takethe position shown in Figures 15 and 150.. In this position of theparts, it will be noted that the valve 44 has been reversed from theposition shown in Figure 14, while the valve 41 remains in the sameposition, and still allows fluid to flow in the same direction as thearrow indicates in Figure 14. This causes the traverse of the tracermechanism to continue but reverses the feed direction so as to move thetracer backwardly toward the relationship between the elements 9 and 20shown in Figure 14a, reversing the direction of the feed motor whilecontinuing the traverse to the right. When the parts have returned tothe position shown in Figures 14 and 14a, the tracer with its feeler isfed against the work edge toward the position of Figures 15 and 1511.Thus the feed motion is alternately reversed while the traverse motioncontinues in the same direction to the right, thus returning the tracertoward the right hand end of the pattern where if the pattern iscontinuous, the tracer is then caused to trace the edge of the patternuntil it again reaches its back edge, whereupon the conditions ofFigures 8 and 9 are again resumed. The action of the motors in returningthe tracer to the back edge of the pattern follows the course but in thereverse direction in so far as the traverse is concerned of Figures 10and 10a to 13 and 13a, as may be understood b reference to thesefigures. Thus when the tracer is presented to the pattern, itautomatically follows completely around the contour thereof andautomatically repeats until stopped, producing the required controls ofthe traverse and feed motors to produce this result with alternate feedsagainst the pattern edge and then away therefrom minute in amount, buthaving the effect of keeping the feeler against the pattern edge andcausing it to move therearound.

From the foregoing it will be seen that the tracer is moved uniformlyalong the pattern with a rapid in and out motion against the edge of thepattern, but of very small amplitude, the feeler remaining in contacttherewith and that when the tracer has once been pressed against theedge of the pattern, the motor mechanisms are from there automaticallycontrolled to cause the feeler to move along and around the edge of thepattern.

This complete closed tracing circuit is provided automatically withoutrequiring any turning of the tracer mechanism as has heretofore beennecessary when moving through more than one quadrant of a completecircuit, and a complete circumference of the feeler operatively engagesthe pattern during this circuit.

It will be noted that the displacement of the feeler with relation tosaid support is in any direction in a plane and such displacement in anydirection is effective in controlling the feed mechanism.

In Figures 16 and 17, a modification has been illustrated in which theinitial controls from the tracer elements 9 and 20 are electrical.Referring to these figures, the stems 43 and 46 instead of beingconnected to pilot valves are connected to resilient switch arms I50 andI5I having oppositely disposed contacts I52 and I53 adjacent to theirfree ends. These contacts are movable back and forth between contactsI54, I55 and I56, I51, these latter being carried by pivoted arms I58,each being adjustably secured to a supporting plate I by screw and slotconnections at I6I. In order to prevent sticking of the contacts and tomaintain the switch mechanism, including these contacts, in a sensitivestate, the foundation plate I69 is shown as fulcrumed on a pivot I andit is provided with a slot IE6 within which is mounted an accentric pinI6! carried by the shaft I68 of a small motor I69. This motor hasaseaesa connected thereto leads I10 and HI from a suitable source ofpower by which the motor may be driven, thus this, through the action ofits eccentric pin I61, oscillating the plate I69 rapidly through a verysmall are. As the levers 40 and 4| are rocked by motion of the tracerelement 9 and relative motions between this element 9 and the element20, contacts are made between the movable contact elements I52 and I53and their adjacent elements I56, I55 or I56, I51, thus -completingelectric circuits through solenoids I 86, I8 I I82 and I83 which rockthe T-shaped levers I 84 and I85 connected through links I36 and I8!with the controlling valves 588 and I89, which, in turn, control fluidunder pressure to the longitudinal slide motors I26 and the cross lidemotor I2I. The amplitude of motion of the T-shaped levers I84 and H35 islimited by contact with opposite sides of notches H95 and I95 ofangularly adjustable limit plates 19'? and I 93. The action of thismechanism is substantially the same as heretofore described so that nofurther description appears to be here necessary.

In Figure 18 a further modification is shown of hydraulic actuation.Referring to thi figure, a different form of hydraulic valve from thatshown in Figures 1 to 15, is illustrated, together with differentconnections to the inner and outer tracer elements 26 and 9. Between thepilot valve 2M! and its ported valve casing 2c: is a sleeve 202. Thissleeve has an extension 2613 which i connected through a link 2% to apost 265 secured to the table or flange the which is carried by theupper end of the outer tracer element 9. The

valve 2% isconnected through a link 2H1 with the upper end portion ofthe tracer element 20, passing looselythrough a hole 2! I through theupper end portion of the tracer element 9. It is understood that thereare two of these valves 26!) with their sleeves 282 arranged at rightangles to each other and taking the places of the pilot valves 44 and llof the constructions previously described, the valve and its sleevecorresponding in position to the valve 44 controllin the front and backfeed motor i2l shown in Figure 7, and the pilot valve 209 with its partscorresponding in position to the pilot valve 41 of Figure 7,.controllingthe longitudinal slide motor 29. The sleeve 202 has ports 2i5, 2E6 and 2H which serve as extensions of the main valve casing ports 2E8, 2|9 and229, respectively, which correspond to the one end, the central, and theother end ports of the spool valve shown in Figures 1. to 15, but theeffective positions of these port 2 l8, 2I9 and 22B is changedlengthwise of the valve cylinder by axial motion of the sleeve 283, thusto correspondingly change the efieotive position of the valve 200 withreference to the main valve ports 2E8, ZIQ and 220. The arrangement issuch that the valve 2% is effective to change the supply and dischargeto the feed and traverse motors corresponding thereto partl inaccordance with the position or" the valve 28% and partly in accordancewith the position of the sleeve 202, and the combined eiiects of thesleeve and valve to control the directions of motion of the feed andtraverse or the cross and longitudinal slides, is identical with thatproduced by the single valve arrangement operated by the compositemotions of the flange or table 353 and the inner tracer element 22 apreviously described. I

In Figures 1i) to 22, inclusive, the application of a pattern and traceras previously described is shown to a turret lathe to control theoperation of the tool at oneof the tooling stations of 10 the turret. Asshown in these figures, the lathe comprises the bed 390 having the usualheadstock 3t carrying the rotating spindle provided with a chuck 38 2for supporting the work piece 393. At 3&4 is shown the usuallongitudinally slidable carriage on which is supported the cross feedslide 3&5 mounted for front and back feed motion, this feed slidesupporting the 'indexable turret 396 of conventional type, as shownthere being six turret faces, each carrying one or more tools. One ofthese tools at 30'! is to be controlled by the pattern and tracermechanism. The tracer mechanism is shown as extended upwardly coaxialwith the turret and including the tracer head 33% pivoted at the top ofthe turret by a flange 33? (Figure 20) axially fixed to tracer head 383and encased in member 359 fixed to the turret. At 32!} is shown a tanksupport at the tail end of the machine in which is mounted the hydrauliclongitudinal slide actuating motor I2?! provided with a piston 315 whichmay be secured to the back portion of the traversing carriage 394. At3H5 (see Figure 19) is shown a rotary reversible hydraulic motor whichtakes the place of the reciprocating motor l2l of Figure 7 and isarranged to operate the cross slide ieeding mechanism, to this end beingadapted to rotate a feed screw 3H. At 329 is illustrated theconventional carriage traverse wheel by the rotation of which thecarriage 3% may be given its hand actuated traverse. A rockable handle32! may be provided by the rocking of which any suitable powertraversing mechanism may be thrown into or out of controlling relationto drive the carriage 39 3. This is old and well known in the art, butmay be, if desired, oi the construction shown in Figure 9 or" the LovelyPatent No. 2,066,144 granted June 25, 1935. This power traversemechanism may be employed during the operation at the other toolingstations of the turret, but is thrown out when the controls by thepattern and tracer are to be brought into operation.

The support 3m is shown as connected to the headstock by a bar 325 onwhich is rockably mounted between a pair of adjustable collars 328 and32? clamped to the bar 325, a pattern holder 328. This may be turnedupwardly about the bar 325 as an axis into the inoperative positionshown in Figure 20 and in full lines in Figure 21, and there held by alatch 3 i 3, or it maybe rocked down to horizontal position shown indotted lines in Figure 21 in operative relation to the upwardlyprojecting tracer head 3M3. The pattern holder 323fcarries the pattern322 which may be adjustable toward and from the axis or" the part 325 asby manipulation of the adjusting screw 339. By this means the edge ofthe pattern opening 335 may be brought into such relation to the ieeleras to cause the valves controlled by the feeler to operate to producethe desired tracing action of the tracer along the pattern edge aspreviously described.

At 346 on Figures 19 and 20 is shown a motor having a fluid pump 345actuated thereby which supplies the fluid under pressure from a suitablesource to the tracer controlled valve mechanisms through the pressurepipe 3% which leads to the distribution box 3 53. This box contains thecontrolling valves fer the feed and traverse motors which are connectedthrough suitable connections housed within the tube 3% to the mechanismhoused within the tracer head 3%. The tube 3M supporting the box 343 isslidable through the vertically pivoted guide sleeve 335. From thedistribution head 343 pipes extend to a valve caslli ing 345 from whichextend a pair of flexible pipes 345 and 341 to opposite sides of thefeed motor 315 and a pair of flexible pipes 343 and 349 to opposite endsof the traverse motor 120. A discharge pipe 35!] leads from thedistributing chamber 343 back to discharge. In this embodiment of theinvention the pipes 342, 350, 346, 341, 348 and 349 perform thefunctions of the pipes 38, 9|, I22, I23, l24 and I25, respec tively, ofthe diagrammatic showings of Figures 1 and 7 and are connected into thevarious parts in the same manner, the valve mechanisms 44, 4?, l8 and 79forming part of the tracer mechanism and being carried by the turret.

Ihe valve 343, as shown in Figure 22, has a valve plug 355 havingsuitable ports 356 and 35'! which may be brought in registry with thepairs of pipes 348 and 34'! and 348 and 359, respectively, in order thatwhen the tracer mechanism is not employed, as when tools of the othertooling stations are to be operated, opposite sides of each of thesemotors 318 and Hi] may be connected together so that the carriage 304and cross slide 305 may be moved freely without interference from thesemotors. When the tooling station of the turret where control of the toolfrom the pattern is desired, the tool is brought into proper angularposition to operate on the work, the valve plug 355 is turned toopen theports of pipes 3&8 and 341, 348 and 369 and to connect them into thedistributing chamber 3 53. The motors me and 316 are then under controlof the valves actuated by the tracer. The pattern is swung down intooperative relation to the tracer which has been moved into position tocooperate therewith, whereupon the turret tool is under the full controlof the tracer mechanism and cuts the work in accordance with the patternand repeats so long as the pattern is in position for the tracer feelerto bear against its edge and the power supply is in operation.

From the foregoing description of certain embodiments of this inventionand applications thereof to a machine tool, it should be evident tothose skilled in the art that various other changes and modificationsmight be made without departing from the spirit or scope of thisinvention.

I claim:

1. In combination, a tracer comprising a pair of normally parallelslightly spaced elements, one of said elements having a feeler, of ,a,support to which said elements are pivoted for lateral motion, the pivotfor said feeler element being spaced from said feeler further than thepivot for the other of said elements, whereby motion of said feeler in adirection to contact said other element thereafter moves said otherelement therewith and remote from said feeler at a faster rate, acontrol member carried by said support,

operative connections from said elements to said member, and power meansfor moving said tracer controlled by said control member.

2. In combination, a tracer comprising a pair of normally parallelslightly spaced elements, one of said elements having a feeler, asupport to which said elements are pivoted for lateral motion, the pivotfor said feeler element being spaced from said feeler further than thepivot for the other of said elements, whereby motion of said feeler in adirection to contact said other element thereafter moves said otherelement therewith and remote from said feeler at a faster rate, acontrol member carried by said support, an operative connection fromsaid feeler element to said control member, and a connection from saidother element to said operative connections for modifying the controleffected by motion of said feeler element.

3. A tracer comprising a support, a pair of normally coaxial elements,the outer of said elements having a pattern feeler at one end and beingpivoted for universal swinging motion to said support, the inner of saidelements having an end positioned adjacent to said feeler normallyslightly spaced from said feeler element but adapted to be contactedthereby and moved on motion of said feeler element out of normal angularposition, said other element being universally pivoted to said supportnearer to said feeler than is said feeler element, yielding meanstending to hold said elements in normal coaxial relation, a flangemember secured to said feeler element on the opposite side of its pivotfrom said feeler, a pair of levers fulcrumed on said flange member atpoints spaced angularly about its axis, a pair of radially arrangedcontrol devices carried by said support corresponding to the angularspacing of said levers, a connection from one of each lever to thecorrespondingly positioned control device, and a connection from theinner end of each lever to said other element, whereby the angularposition of said feeler element relative to said support modified by theangular position of said inner element relative to said support controlssaid devices.

4. A tracer comprising a support, a pair of normally coaxial elements,the outer of said elements having a pattern feeler at one end and beingpivoted for universal swinging motion to said support, the inner of saidelements having an end positioned adjacent to said feeler normallyslightly spaced from said feeler element but adapted to be contactedthereby and moved on motion of said feeler element out of normal angularposition, said other element being umversally pivoted to said supportnearer to said feeler than is said feeler element, yielding meanstending to hold said elements in normal coaxial relation, a pair ofvalve mechanisms angularly spaced apart about the normal axis of saidelements each of said valve mechanisms comprising a ported casing, asleeve fitting within said casing for axial motion relative thereto andhaving ports communicating with the several casing ports throughout thesliding range of said sleeve, a valve slidable Within said sleeve andhaving ports for selective connection with said sleeve ports,connections between one of said elements and said sleeve and between theother of said elements and said valves, and angularly disposedpower-moving means controlled by the relative axial positions of saidvalves and their respective sleeves.

5. A tracer comprising a support, a pair of normally coaxial elementsone within the other and normally slightly spaced apart, the outer ofsaid elements having a feeler at one end, said feeler element beingpivoted to said support spaced from said feeler, the inner element beingpivoted to said support nearer to said feeler than is said feelerelement, a tubular casing carried by said support, a pair of spacedabutments in said casing, said casing having annular shoulders againstwhich said abutments may engage, a spring between said abutments tendingto hold said abutments against said shoulders, stems projecting fromsaid abutments and engaging said elements and yieldingly holding saidelements in coaxial relation, control devices carried by said support,

13 and operative connections between said devices and said elements.

6'. In combination, a tracer comprising a pair of normally parallelslightly spaced elements, one of said elements having a feeler, asupport to which said elements are pivoted for lateral motion, the pivotfor said feeler element being spaced from said feeler further than thepivot for the other of said elements, whereby motion of said feeler in adirection'to contact said other element thereafter moves said otherelement therewith and remote from said feeler at a faster rate, a pairof relatively angularly arranged pilot valves carried by said support,an operative con nection from said feeler element to each of said pilotvalves, a connection from the other of said elements to each of saidoperative connections for modifying the effects on said pilot valves ofthe motion of said feeler element, angularly related direction moving:means for said tracer including a pair of reversible hydraulic motors,and a pair of reversing valves controlled by said pilot valves forcontrolling said hydraulic motors.

7. In combination, a tracer comprising a pair of normally parallelslightly spaced elements, one of said elements having a feeler, asupport to which said elements are pivoted for lateral motion, the pivotfor said feeler element being spaced from said feeler further than thepivot for the other of said elements, whereby motion of said feeler in adirection to contact said other element thereafter moves said otherelement therewith and remote from said feeler at a faster rate, anelectrical circuit control member carried by said support, an operativeconnection from said feeler element to said control member, a connectionfrom said other element to said operative connection for modifying thecontrol effected by motion of said feeler element, power means formoving said tracer, and a control for said power means including anelectric circuit controlled by said control member.

8. A tracer comprising a support, a pair of normally coaxial elements,the outer of said elements having a pattern feeler at one end and beingpivoted for universal swinging motion to said support, the inner of saidelements having an end positioned adjacent to said feeler and normallyslightly spaced from said outer element but adapted to be contactedthereby and moved on motion of said outer element to a sufficient extentout of normal angular position, said inner element being universallypivoted to said support nearer to said feeler than is said outerelement, a control member, and operative connections from both of saidelements and spaced from their pivots to said control member.

9. A tracer comprising a support, a pair of normally coaxial elements,the outer of said elements having a pattern feeler at one end and beingpivoted for universal swinging motion to said support, the inner of saidelements having an end positioned adjacent to said feeler and normallyslightly spaced from said outer element but adapted to be contactedthereby and moved on motion of said outer element to a sufiicient extentout of normal angular position, spring means engaging said elements andtending to hold said elements coaxial and to return them to coaxialrelation when displaced therefrom, said inner element being universallypivoted to said support nearer to said feeler than is said outerelement, a control member, and operative connections from both of saidelements and spaced from their pivots to said control member.

10. In combination with a feeler, power means for moving said feeler ineither direction in two angularly related paths, a pair of relativelymovable elements operatively connected to said feeler and to each otherto be moved relatively in one direction during a predetermined extent offeeler motion from a predetermined position in directions correspondingto each of said paths and in the opposite direction and at a differentrate during a further motion of said feeler in the same direction inexcess of said extent, and a control for each of said feeler movingmeans responsive in its control direction to the relative positions ofsaid elements.

WILLIAM L. TANCRED.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,381,752 Scheyer June 14, 19211,588,856 Shaw June 15, 1926 1,677,131 Cole et a1 July 17, 19281,952,230 Anderson Mar. 27, 1934 2,036,362 Sassen et a1. Apr. 7, 19362,047,181 Ferris July 14, 1936 2,199,465 Martellotti May 7, 19402,226,677 Vikham Dec. 31, 1940 2,263,764 Elberty Nov. 25, 1941 2,331,337Meyer Oct. 12, 1943 2,331,817 Turchan et al Oct. 12, 1943 2,334,956Ridgway Nov. 23, 1943 2,345,218 Rosen Mar. 28, 1944 2,372,426 JohnsonMar. 27, 1945 2,372,604 Rosen Mar. 27, 1945 2,389,426 Turchan Nov. 27,1945 2,409,903 Schwartz Oct. 22, 1946 2,436,373 Barnes Feb. 24, 1948ertificate of Correction Patent N0. 2,562,284 July 31, 1951 WILLIAM L.TANCRED' It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 12, line 25, after one insert end; line 27, for inner read other;same line, for other read inner;

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOflice.

Signed and sealed this 9th day of October, A. D. 1951.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

